# C851 — Close the first twenty-step explanatory checkpoint

## Question

What did the complete list holdout add to the common grammar?

## Inputs

```json
{}
```

## Sources

```json
[
  "C832–850"
]
```

## Opened utc

2026-09-28T02:35:35.445034+00:00

## Results

```json
{
  "checkpoint": {
    "path": "deliverables/490d_Chronological_Families_Checkpoint_C851.md",
    "sha256": "18816601d66beb94848c9353dd59c9d2cbc13c64b9fad842459de3a7d3e78369",
    "bytes": 1453
  }
}
```

## Finding

The first transfer succeeds with one explicit enrichment: category predicates and declared order remain attached to source rows. Equal totals are now traced to exact constraints rather than treated as interchangeable objects.

## Reassessment

Reconstruct the full paired-anchor field from its original digit registers.

## Checks

```json
{
  "twenty": true
}
```

## Closed utc

2026-09-28T02:35:35.445486+00:00

## Record provenance

Exact record hash: `05927a24dbc74d44248e1825e477182d508a0b89c5033bb517860bd66006b9aa`

Source journal: `Research_Cycles/C0832_C0931/journal.json`